The XCR3D filament connector used when connecting two filaments is easy to connect very short filaments. However, it is not as easy as you think when connecting slightly longer filaments on spool. So I made a stand to make it easier to use the filament connector.
Four m3 X 4.5 X 3~4 heat inserts are required.
Two 12mm m3 bolts.

PETG recommended.

The filament connector stand and filament connector are very tight, so you need to apply some force to insert them.  If printed with ABS, it may not fit due to shrinkage.